Mauro didn't really fit into the tank, he's not a bad guy by any stretch of the imagination, he just didn't really "belong" properly. I think his autism is rather subdued, the kids quiet and very self reserved, likes to stay in his lane and mind his business. It's only now that he realizes where the fuck he's ended up, and doesn't want to his family or friends involved in this shit either. It's a smart but sad move from him, but now they're effectively 3 fishes down and there's still 4 weeks to go. They need to bring in a new fish ASAP tbh.
edit note: I say 3 because damniel is a plant and really shouldn't be there but it wouldn't be a MDE production without some absolute bullshit